This invention relates to motor vehicle suspension components and particularly to a steering knuckle assembly adapted to support a steerable wheel.
Conventional motor vehicles have a steering knuckle which is typically constructed as a one-piece forged or cast unit. Such integral units may include a wheel bearing carrier, torque arms for supporting a disc type brake caliper, and points of attachment for suspension components. Although such steering knuckles perform satisfactorily, it is desirable to provide enhanced structural and cost optimization for these units. It is particularly desirable to reduce the weight of the steering knuckle assembly since weight reductions in this area provide the two-fold advantage of reducing total vehicle weight and suspension unsprung mass. Overall vehicle weight reductions improve performance and fuel efficiency. Reductions in unsprung mass are desired to enhance vehicle ride and handling. It is further desirable to provide an improved steering knuckle assembly which can be produced at a lower cost than current designs. Another desirable feature for a steering knuckle assembly is the ability to adapt it to different motor vehicle applications.
The objective of the present invention is to provide the above-mentioned desirable features for a vehicle steering knuckle. A preferred embodiment of a steering knuckle assembly according to this invention is formed from two mechanically attached components. A bearing carrier component may be fabricated by conventional casting or forging processes and includes the wheel bearing carrier and torque arms for supporting a disc brake caliper assembly. The remaining portion of the steering knuckle assembly is formed by a concave shell-shaped housing preferably manufactured using metal stamping processes. This composite structure provides a significant weight advantage and cost advantage as compared with conventional designs primarily due to the use of stamped components. The steering knuckle assembly according to this invention may be adapted to different motor vehicle applications by changing the configuration of the stamped housing, enabling the same cast or forged bearing carrier component to be used for various applictions. When assembled, the steering knuckle assembly according to a preferred embodiment of this invention mechanically traps the wheel bearing within the steering knuckle assembly.
The steering knuckle assembly according to this invention further enables the stamped knuckle housing component to have a simplified configuration which eliminates the protruding steering arm of conventional steering knuckle designs. Instead, a novel steering link is employed which is fastened directly to a side wall portion of the knuckle housing.
In accordance with another feature of the steering knuckle assembly according to this invention, a novel means for fixing the ball joints of the vehicle suspension system to the steering knuckle is disclosed. The attachment system according to this invention eliminates the necessity of providing bushings having internally tapered bores as attachment sockets. The attachment system employs a hemispherically shaped seat formed by the knuckle housing which mates with complementary shaped surfaces of the ball joint attaching stud.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.